The present invention relates to a modular gearbox assembly, and more particularly to a gearbox housing assembly of the modular gearbox assembly.
In applications which require high strength for static or dynamic loading, a gearbox housing is typically constructed of a main housing portion that is commonly die cast metal (aluminum and steel being two common materials). The housing provides the structural strength to withstand tensile and compressive loads, for example, while also shrouding the gears located within the main housing portion. The potential environments for high-strength gearbox housings vary greatly, but generally, the secondary purpose of the housing is to keep unwanted substances out of contact with the gears.
FIG. 6 illustrates a portion of a prior art gearbox housing designed for a high strength application. The main housing portion 20 can be die cast as a single, solid part including a central cavity 24 for positioning the gears. A supplementary housing portion (not shown) is used to cover the open side of the main housing portion 20 once the gears (not shown) are positioned inside the cavity 24. The main housing portion 20 is formed to include attachment structure 28 for joining with an input drive source (not shown) such as an electric motor or other prime mover. Additionally, the main housing portion 20 is formed to include primary mounting structure 32 for fixing the gearbox housing to a supplementary structure, such as a stationary mounting rod. The main housing portion 20 is formed to include a plurality of strengthening ribs 36, some of which are shown in FIG. 6.
Because the main housing portion 20 is relatively complex, including a gear cavity, attachment structure, primary mounting structure, and at least some additional strengthening features, the component is relatively complex and expensive to produce, requiring dedicated tooling and maintenance. Any variations to any feature of the main housing portion 20, such as a differently-shaped or differently-sized primary mounting structure 32 requires completely separate tooling. For a manufacturer that makes many types of gearbox housings for different customers or applications that each has at least one unique feature, the costs for separate tooling and maintenance can become quite extensive.
In addition to the inherent complexity and expense in manufacturing, the resulting gearbox housing is unduly heavy because of its all-metallic construction. Specifically, in many applications, the gearbox housing is designed for high-strength along a single axis, and the gearbox housing includes a substantial amount of excess material, which provides an abundance of strength in certain areas that do not require such strength.